It is against the law for any driver to use or to carry a device which can interfere, predict or detect the location of any official traffic monitoring device, including and especially mobile or static speed cameras. The standard fine for this offence is €75 (and 4 points if you have a German Drivers Licence).
GPS or sat navs which give warnings about fixed speed camera locations are not permitted either, this function must be deactivated before the navigation system can used.